Abstract: We study experimentally the propagation of internal waves in two different three-dimensional (3D) geometries, with a special emphasis on the refractive focusing due to the 3D reflection of obliquely incident internal waves on a slope. Both studies are initiated by ray tracing calculations to determine the appropriate experimental parameters. First, we consider a 3D geometry, the classical set-up to get simple, two-dimensional (2D) parallelogram-shaped attractors in which waves are forced in a direction perpendicular to a sloping bottom. Here, however, the forcing is of reduced extent in the along-slope, transverse direction. We show how the refractive focusing mechanism explains the formation of attractors over the whole width of the tank, even away from the forcing region. Direct numerical simulations confirm the dynamics, emphasize the role of boundary conditions and reveal the phase shifting in the transverse direction. Second, we consider a long and narrow tank having an inclined bottom, to simply reproduce a canal. In this case, the energy is injected in a direction parallel to the slope. Interestingly, the wave energy ends up forming 2D internal wave attractors in planes that are transverse to the initial propagation direction. This focusing mechanism prevents indefinite transmission of most of the internal wave energy along the canal.

Cite: Pillet G. , Ermanyuk E.V. , Maas L.R.M. , Sibgatullin I.N. , Dauxois T.
Internal wave attractors in three-dimensional geometries: trapping by oblique reflection
Journal of Fluid Mechanics. 2018. V.845. P.203-225. DOI: 10.1017/jfm.2018.236 WOS Scopus РИНЦ OpenAlex

Identifiers:

Web of science:	WOS:000430473200007
Scopus:	2-s2.0-85045767157
Elibrary:	35508028
OpenAlex:	W3098282242

Citing:

DB	Citing
Scopus	24
OpenAlex	25
Elibrary	24
Web of science	22

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